Formal:
* Savez-vous déjà? (Do you already know?)
* Êtes-vous déjà au courant? (Are you already aware?)
Informal:
* Tu sais déjà? (Do you already know?)
* T'es au courant? (Are you aware?)
* Tu connais déjà? (Do you already know?)
The best way to choose the right phrase depends on your level of formality and the context of the conversation.